This invention relates to a peptide product and to a method of making it by hydrolyzing protein. In particular, it relates to a two-stage enzymatic hydrolysis of whey protein concentrate using fungal enzymes to produce a peptide product that can be used to make a milk replacement and as a component in other food products.
Because many people are allergic to the proteins that are in milk, milk proteins need to be broken down into non-allergenic peptides before they are used in food products. It is necessary to break down almost all of the allergic proteins since only a small amount of the intact protein can cause the reaction. However, it is difficult to break down some of the proteins in milk and even low concentrations of certain proteins in a food product can cause allergic reactions in some people. Also, during the process of converting the milk proteins into peptides various bitter-tasting or off-tasting products can be formed. These bad tastes are difficult or impossible to remove and can be so strong that they cannot be hidden by the addition of sugar or flavors. Also, products that leave various after-tastes can also be formed. Some products have an unacceptably high bacterial count and/or a low protein efficiency ratio (PER, which is a measure of the effectiveness of the protein in adding mass to a rat). Some of the recent past published procedures called for fractionating the bitter peptides into two fractions. Some of these fractions were not bitter. Unfortunately, these fractions seemed to be very high in non-essential amino acids. To use these non-bitter fractions called for supplementation with several essential amino acids (Cordle). Since those amino acids are nutritionally important, the resulting product is nutritionally deficient. If the product has a dark color, that may also be unacceptable for use in light-colored products.
At the present time there are no commercially available peptide products that meet all these often-conflicting requirements.
In the process of this invention, a protein source is digested (hydrolyzed) in two stages using fungal enzymes, then dried to produce a mixture of peptides and free amino acids. Unlike some of the peptide products produced by other methods, the peptide product of the method of this invention retains the full nutritional value of the protein from which it was made. Also, it has essentially no non-diary flavor and does not have a bitter taste or an after taste. Because all of the allergy-causing proteins are broken down into peptides and amino acids in the process of this invention, the product is non-allergenic. It is light-colored and can be easily substituted for milk protein in various food products.